Apparatus for manufacturing a tray for packaging goods in shrinkable sheeting

ABSTRACT

The tray consists of flexible material, preferably cardboard, and has a polygonal base, an even number of corners, and vertical side walls. Alternating side walls have outwardly directed, infoldable extension flaps. The two corner portions between each side wall and the adjacent side walls are tucked in toward the side wall provided with an infoldable flap and are covered by the flap, which has a tapered end portion, which is locked in an aperture at the edge of the bottom of the tray.

United States Patet Bauer 1 Feb. 119, 11974 [541 APPARATUS FOR MANUFACTURING A 2,887,022 5/1959 Lubersky et a1. 93/53 SD TRAY FOR PACKAGING GOODS 1 3,492,923 2/1970 Stenberg l 93/51 R SHRINKABLE SHEETING 3,512,459 5/1970 Frank 93/51 R 76 I t E h d B H d 1 men or lgz gg 2 :2 eweg Primary Examiner-Andrew R. Ju'hasz Assistant ExaminerLeon Gilden [22] F1led: Jan- 11, 19 Attorney, Agent, or Firm-Fleit, Gipple 8L Jacobson [21] Appl. No.: 217,018

[57] ABSTRACT [30] Foreign Application Priority Data Jan 19 1971 German 2102431 The tray consists of flexible material, preferably cardy board, and has a polygonal base, an even number of corners, and vertical side walls. Alternating side walls g 93/51 93/49 fig 17;: have outwardly directed, infoldable extension flaps. [58] Fie'ld I 30 32 The two corner portions between each side wall and 206/6 51 2, 5 the adjacent side walls are tucked in toward the side wall provided with an infoldable flap and are covered by the flap, which has a tapered end portion, which is [5 6] References Cited locked in an aperture at the edge of the bottom of the UNITED STATES PATENTS 1/1960 Pierce 93/51 R tray.

2 Claims, 19 Drawing Figures PATENI FEB 1 9 1914 SHEET 3 OF 9 Fig.12

PATENT max 9197 4 SHEET 0F 9 PAIENIE FEB 1 91974 SHEET 5 BF 9 PAIENTED FEB 1 91974 SHEET 8 OF 9 Fig.18

APPARATUS FOR MANUIF ACT b G A TRAY FOR PACKAGING GOODS llN SHRINTQABILIE SHEETTNG This invention relates to a tray which serves for packaging goods in shrinkable sheeting and consits of flexible material, preferably cardboard, and has a polygonal base, an even number of corners, vertical sidewalls, and to a process and apparatus for manufacturing the tray. Trays are made from flat cardboard blanks and have a vertical rim and serve to receive products, which are subsequently enclosed with shrunk transparent sheet ing. Industry is increasingly offering lump products for sale which have been packaged in shrinkable transparent sheeting. Such a package is inexpensive and holds the product in position and has the advantage that a potential customer can see the product. For instance, it is no longer necessary to provide crossing webs of corrugated paper between a plurality of similar articles in one package to keep these articles from rattling and from bumping on each other, because the products packaged in shrinkable sheeting cannot move in the package. The use of the shrinkable transparent sheeting increases the attractiveness of the product. This kind of package also promotes the present trend in retail sales to sell small sets of products rather than individual items.

F or cashand-carry and self-service operations, larger transparent packages are increasingly required so that the customer can immediately inspect the contents and need no longer tear open the carton for such inspection. These requirements to be met by a modern package can be fulfilled by the use of shrinkable sheeting.

To ensure that the items held together by shrinkable sheeting can be stacked and transported, the packages must have a certain stability and a uniform external shape. For this reason, the products to be packaged with sheeting which is shrunk onto the products are filled into cardboard trays which have a continuous peripheral rim which contributes to the stabilization of the profile. Various forms of such cardboard trays are known.

Fit-over cartons are known, which are made from prefabricated flat cardboard blanks as trays having two side walls, which have protruding lugs and are erected, whereafter the lugs are infolded and are then covered by an infoldable flap of the side wall which is disposed between the two side walls mentioned first. The infoldable flap of the two-ply side wall is anchored in the bottom of the tray by locking noses, which are inserted into apertures. These known trays have the disadvantage of involving a large consumption of cardboard because one-half of all side walls must be made from twoply material.

It is also known to form trays in that side walls are erected from a flat cardboard blank and the overlapping ends of these side walls are then glued together. The glueing is an additional step in the manufacturing process and this step is not desired because it slows down the production, and the servicing of the nozzles through which the adhesive is applied involves additional costs.

It is an object of the invention to provide materialsaving trays made without adhered joints, and a process and apparatus for the manufacture of such trays.

In a tray of the kind mentioned first hereinbefore, this object is accomplished in that alternating side walls have outwardly directed, inflodable extension flaps, that the two corner portions between each side wall and the adjacent side walls are tucked in toward the side wall provided with an infoldable flap and are covered by the flap, which has a tapered end portion, which is locked in an aperture at the edge of the bottom of the tray.

The design according to the invention results in material-saving, stable trays which have no glued joints. The trays will not be destroyed even by relatively large tensile forces exerted on the side edges because the overlapping flaps hold the tucked-in comer portions reliably in position.

In a particularly preferred embodiment of the tray, the same has an octagonal bottom and two pairs of opposite long side walls and short side walls which connect the long side walls, the corner portions between adjacent side walls are tucked in toward the short side walls, which have extension flaps, these corner portions are covered by the extension flaps of the short side walls, and the extension flaps have tapered end portions, which are locked in apertures at the edge of the tray bottom. The short side walls extend suitably at right angles to the bisector of the angle between the ad jacent side walls. This tray according to the invention may be made from a flat rectangular blank, e.g., of cardboard, in that bend lines are scored into the blank to define the side walls, these bend lines extend along the lower and lateral boundary lines of the side walls and along the bisector of the angle between two side walls, and each of the flaps which cover the tucked-in corner portions are formed by punching out two pairs of right-angled triangles, each of which has one leg which forms part of the side edge of the flap and another leg which forms the top edge of the tucked-in corner portion which engages the inside of the short side wall, and each flap is separated by a scored fold line from the short side wall.

in the process provided by the invention of manufac turing the trays, the fold lines which define the side walls are scored into the flat blank, the apertures for locking the tongues of the flaps are punched into the tray bottom so as to adjoin the fold lines, and the covering flaps are punched from the base material, whereafter the side walls of the tray are erected, the corner portions are tucked in, the flaps are bent over the tuckedin corner portions, and the tongues of the flaps are inserted into the bottom apertures.

The apparatus according to the invention for carrying out the process of the invention comprises a pivoted arm, which is provided with vacuum cups and serves to take flat tray blanks from a magazine, a well, which in cross-section conforms to the tray and which receives a plunger and further comprises processing stations disposed in the well one over the other, and comprising pivoted blades, which serve to tuck in the corner portions between the side walls of the trough and which are controlled by camwheels, angle members which are pivotally movable through and are controlled by camwheels and serve to infold the flaps, and means for ejecting the trays and for feeding them to the filling stations. The folding stations which define the well are suitably diagonally movable for adaptation to sheets of different sizes.

lllustrative embodiments of the invention will be explained more fully hereinafter with reference to the drawing, in which FIG. 1 shows a tray folded to final shape,

FIG. 2 a flat tray blank for use in the manufacture of a tray according to FIG. 1 with prescored bend lines indicated by dotted lines,

FIG. 3 a tray rim corner folded into final shape, and

FIG. 4 a blank comer area for forming the folded corner shown in FIG. 3.

FIGS. 5 to show the several steps used to fold the corners.

FIGS. 11 and 12 show tray rim corner areas as shown in FIG. 3, folded to final shape.

FIG. 13 is a diagrammatic sectional view showing a three-stage tray-erecting and -manufacturing machine,

FIG. 14 a diagrammatic top plan view showing the machine of FIG. 13,

FIG. 15 a sectional view taken on line l--I of FIG. 13, FIG. 16 a sectional view taken on line IIIIII in FIG.

FIG. 17 a sectional view taken on line IVIV in FIG. 15,

FIG. 18 a sectional view taken on line VV in FIG. 17, and

FIG. 19 a sectional view taken on line Vl-VI in FIG. 17.

The carboard tray shown in FIG. 1 has been folded from a flat rectangular cardboard blank 2 shown in FIG. 2 and having the length 1 and the width b. The finished tray 1 comprises mutually opposite, longer side walls 18 and 19, which are connected by cornerforming short side walls 20. The portions which form the side walls 18, 19, 20 are defined on the fiat cardboard blank by the bottom-defining fold lines 3, 6, 9. To facilitate the folding of the side walls, the bend lines 7, 8, 11, 4, 5, 13 are scored into the flat cardboard blank. The corner-forming short side wall 20 has an extension flap 21, which is foldable about the prescored fold line 10. To form the flap, right-angled triangles 22 are punched out, which have one leg 15 defining a portion of the flap 2] and another leg 16 defining a portion of the tucked-in corner portion 23. When the side walls have been erected and the corner portions 23 have been tucked in so that one half of each corner portion on one side of the angle-bisecting fold line 13 engages the inside of the adjacent longer side wall and the other half of each corner portion engages the inside of the corner-forming short side wall, the flap 21 is folded over the tucked-in corner portion until the tongue 17 of the flap snaps into the aperture 14.

The blank shown in FIG. 2 is designed so that the height d of the corner-forming short side wall 20, inclusive of the extension flap 21, somewhat exceeds twice the height of the longer side walls 18, 19 so that a reliable engagement of the locking tongue 17 in the aperture 14 is ensured when the flap has been reversely bent. The width 0 of the flap which has been formed by punching out the angle portions 22 is equal to the width of the corner-forming short wall 20.

When it is desired to fold a tray in which the longer side walls are higher, the comer areas of the blank may be designed as shown in FIG. 4, where the comer portions are lower so that the free end portion of the reversely bent flap 21 can be reliably snapped into the aperture 14. In the blank shown in FIG. 4, the height b of the short side walls 20 is smaller at the corner portions by the distance e than the height a, of the longer side walls. The use of this blank results in trays which have higher side walls without need for additional material for the tucked-in comer portions.

FIGS. 3 and 5-10 show the several steps of folding a tucked-in corner portion from a blank as shown in FIG. 4.

When the longer side walls 18 and 19 have been erected, the tray has the form shown in FIGS. 5 and 6. The corner portions 23 between the side walls have not yet been folded about their angle bisector. When the side walls have been erected, the comer portions 23 are tucked in toward the short side walls 21) to form the corners. To this end, pressure is applied along the prescored bend lines 13 until the condition shown in FIG. 7 results. The flap 21 is then bent over the tucked-in comer portions 23 until the end portion 17 enters the recess 14 in the bottom of the tray. The several steps of the manufacturing process are illustrated in FIGS. 7-10. FIGS. 312 show the corner folded to final shape. When tension is exerted on the longer side walls 18 and 19, the folded corners can open only when the tucked-in comer portions 23 erect from their tucked-in position to their initial position. The tucked-in corner portions cannot erect, however, because they are under pressure applied in the direction of the arrows shown in FIG. 11 and this pressure holds down the tucked-in corner portions.

An apparatus for folding the tray according to the invention is diagrammatically shown in FIGS. 1319.

The flat cardboard blanks 2 are supplied through a feed chute 29 to the tray-erecting machine 30. Each tray blank is lifted from the feed chute 29 by vacuum cups 33, which are carried by a lever, which is pivoted on the pivot 32, and are conveyed by a conveyor to engage the stop 34 in a position over the well 35. A plunger 37 which is movable up and down is disposed over the well 35, which comprises four folding stations conforming to the bottom of the tray. The side walls 18, 19 are erected in that the tray blanks are forced into the well. The well 35 contains two processing stations 38 and 39, in which the corner portions 23 are tucked in and the flaps 21 are infolded. In the first processing station 39, the corner portions 23 are tucked in by the blades 40, which are carried by pivotal arms 42, which are loaded by springs 41. The blades 40 are controlled by camwheels 413 and 44. In this operation, the blades engage the blank along the fold lines 13 and tuck in the comer portion in the direction towards the comerforming short side wall 20. As a result of this tuck-in operation, the wall 20 and the extension flap 21 of this wall are vertically erected. The tucked-in corner portions are subsequently forced against the side wall by the plunger 45. FIG. 16 shows a gripper 46, which in step with the machine moves up and down along the guide rail and moves the tray from the processing station 38 to the processing station 39. In the latter processing station, an angle member 48 mounted on a disc, which is rotatable through infolds the flap 21, which protrudes above the rim of the tray, until the end portion 17 snaps into the aperture 14 at the bottom of the tray. The completely folded tray is subsequently moved by the gripper 46 to position 50, from which it is moved to the filling stations.

What is claimed is:

1. An apparatus for producing a tray with an octagonal bottom, two pairs of opposite long side walls and two pairs of opposite short side walls connecting the long side walls and having extension flaps with tapered end portions, the comer portions between adjacent long side walls being tucked in toward the short side walls and being covered by the extension flaps of the short side walls, and the tapered end portions of the short side walls being locked in apertures at the edge of the tray bottom, said apparatus comprising a pivoted arm having vacuum cups for taking flat tray blanks from a magazine, a well having an opening which conforms to the tray bottom, a first plunger reciprocally mounted over the well, and a plurality of processing stations disposed in the well one above the other including pivotally mounted blades controlled by cam wheels for tucking in the corner portions towards the short side walls, a second plunger for forcing the folded corner portions against the side walls, pivotally mounted angle members controlled by cam wheels and pi tztalb mqtsahls thrfit t j;- 5 91 lqiae the flea gripper means operated by a crank for moving the tray from one processing station to another, and means for ejecting the trays from the processing stations.

2. The apparatus of claim 1 in which means are provided for adapting the well and processing stations to bottoms having difierent sizes. 

1. An apparatus for producing a tray with an octagonal bottom, two pairs of opposite long side walls and two pairs of opposite short side walls connecting the long side walls and having extension flaps with tapered end portions, the corner portions between adjacent long side walls being tucked in toward the short side walls and being covered by the extension flaps of the short side walls, and the tapered end portions of the short side walls being locked in apertures at the edge of the tray bottom, said apparatus comprising a pivoted arm having vacuum cups for taking flat tray blanks from a magazine, a well having an opening which conforms to the tray bottom, a first plunger reciprocally mounted over the well, and a plurality of processing stations disposed in the well one above the other including pivotally mounted blades controlled by cam wheels for tucking in the corner portions towards the short side walls, a second plunger for forcing the folded corner portions against the side walls, pivotally mounted angle members controlled by cam wheels and pivotally moveable through 180* for folding the flaps, gripper means operated by a crank for moving the tray from one processing station to another, and means for ejecting the trays from the processing stations.
 2. The apparatus of claim 1 in which means are provided for adapting the well and processing stations to bottoms having different sizes. 